add a sse demo

Cargo.lock

@@ -1102,9 +1102,9 @@ checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
 
 [[package]]
 name = "js-sys"
-version = "0.3.70"
+version = "0.3.72"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1868808506b929d7b0cfa8f75951347aa71bb21144b7791bae35d9bccfcfe37a"
+checksum = "6a88f1bda2bd75b0452a14784937d796722fdebfe50df998aeb3f0b7603019a9"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -1231,13 +1231,18 @@ dependencies = [
  "log",
  "mime",
  "mime_guess",
+ "serde",
  "thiserror",
  "tokio",
+ "tokio-stream",
  "tower 0.5.1",
  "tower-http",
  "tracing",
  "tracing-subscriber",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
  "wasm-logger",
+ "web-sys",
  "yew",
  "yew-agent",
  "yew-router",
@@ -2150,9 +2155,9 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.93"
+version = "0.2.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a82edfc16a6c469f5f44dc7b571814045d60404b55a0ee849f9bcfa2e63dd9b5"
+checksum = "128d1e363af62632b8eb57219c8fd7877144af57558fb2ef0368d0087bddeb2e"
 dependencies = [
  "cfg-if",
  "once_cell",
@@ -2161,9 +2166,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.93"
+version = "0.2.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9de396da306523044d3302746f1208fa71d7532227f15e347e2d93e4145dd77b"
+checksum = "cb6dd4d3ca0ddffd1dd1c9c04f94b868c37ff5fac97c30b97cff2d74fce3a358"
 dependencies = [
  "bumpalo",
  "log",
@@ -2176,9 +2181,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.43"
+version = "0.4.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61e9300f63a621e96ed275155c108eb6f843b6a26d053f122ab69724559dc8ed"
+checksum = "cc7ec4f8827a71586374db3e87abdb5a2bb3a15afed140221307c3ec06b1f63b"
 dependencies = [
  "cfg-if",
  "js-sys",
@@ -2188,9 +2193,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.93"
+version = "0.2.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "585c4c91a46b072c92e908d99cb1dcdf95c5218eeb6f3bf1efa991ee7a68cccf"
+checksum = "e79384be7f8f5a9dd5d7167216f022090cf1f9ec128e6e6a482a2cb5c5422c56"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -2198,9 +2203,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.93"
+version = "0.2.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "afc340c74d9005395cf9dd098506f7f44e38f2b4a21c6aaacf9a105ea5e1e836"
+checksum = "26c6ab57572f7a24a4985830b120de1594465e5d500f24afe89e16b4e833ef68"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2211,9 +2216,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.93"
+version = "0.2.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c62a0a307cb4a311d3a07867860911ca130c3494e8c2719593806c08bc5d0484"
+checksum = "65fc09f10666a9f147042251e0dda9c18f166ff7de300607007e96bdebc1068d"
 
 [[package]]
 name = "wasm-logger"

Cargo.toml

@@ -24,12 +24,17 @@ yew-router = "0.18"
 gloo = "0.10"
 yew-agent = "0.3.0"
 futures = "0.3"
+wasm-bindgen = "0.2"
+wasm-bindgen-futures = "0.4.45"
+serde = { version = "1", features = ["derive"]}
+web-sys = "0.3.70"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 # server side
 axum = { version = "0.7", features = ["multipart", "tracing", "ws"] }
 console-subscriber = { version = "0.4.0", optional = true }
 tokio = { version = "1", features = ["full", "tracing"] }
+tokio-stream = { version = "0.1", features = ["time"] }
 tower = { version = "0.5", features = ["tracing", "util"] }
 tower-http = { version = "0.6", features = ["util", "trace", "catch-panic"] }
 tracing = "0.1"

src/bin/server.rs

@@ -1,14 +1,18 @@
-use std::{collections::HashMap, str::FromStr};
-
+use axum::response::sse::{Event, KeepAlive};
 use axum::{
-    extract::Path,
+    extract::{Path, Query},
     http::{HeaderName, HeaderValue, Uri},
     response::{Html, IntoResponse, Response},
 };
-use networkd::{ServerApp, ServerAppProps, Route};
+use networkd::{Route, ServerApp, ServerAppProps};
+use serde::Deserialize;
+use std::convert::Infallible;
+use std::{collections::HashMap, str::FromStr};
+use tokio_stream::StreamExt as _;
 use tower_http::{
-    trace::{DefaultMakeSpan, DefaultOnRequest, DefaultOnResponse}, ServiceBuilderExt}
-;
+    trace::{DefaultMakeSpan, DefaultOnRequest, DefaultOnResponse},
+    ServiceBuilderExt,
+};
 use tracing::Level;
 
 use yew::ServerRenderer;
@@ -17,6 +21,28 @@ use yew_router::Routable;
 static INDEX_PAGE: &str = include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/dist/index.html"));
 static DIST_DIR: include_dir::Dir = include_dir::include_dir!("$CARGO_MANIFEST_DIR/dist");
 
+#[derive(Debug, Deserialize)]
+struct SSEEchoParams {
+    #[serde(alias = "s", default)]
+    content: String,
+}
+
+// echo characters one by one
+async fn sse_echo(Query(query): Query<SSEEchoParams>) -> impl IntoResponse {
+    let items: Vec<String> = query.content.chars().map(|c| c.to_string()).collect();
+
+    let stream = futures::stream::iter(items)
+        .map(|s| Ok::<_, Infallible>(Event::default().data(s.clone())))
+        .chain(futures::stream::pending())
+        .throttle(std::time::Duration::from_secs(1));
+
+    axum::response::sse::Sse::new(stream).keep_alive(
+        KeepAlive::new()
+            .interval(std::time::Duration::from_secs(1))
+            .text("keepalive"),
+    )
+}
+
 #[tracing::instrument]
 async fn rendering_pages(
     url: Uri,
@@ -70,6 +96,8 @@ async fn main() -> anyhow::Result<()> {
     let api_router = axum::Router::new();
     let oauth_router = axum::Router::new();
 
+    let sse_router = axum::Router::new().route("/echo", axum::routing::get(sse_echo));
+
     let router = axum::Router::new()
         // not required to login
         .route("/static/*path", axum::routing::get(static_assets))
@@ -81,7 +109,7 @@ async fn main() -> anyhow::Result<()> {
         // nesting router
         .nest("/api/", api_router)
         .nest("/o/", oauth_router)
-
+        .nest("/sse", sse_router)
         // fallback
         .fallback(rendering_pages)
         .layer(

src/frontend.rs

@@ -1,6 +1,6 @@
 pub mod app;
-pub mod pages;
 pub mod components;
+pub mod pages;
 pub mod worker;
 
 pub use app::*;

src/frontend/app.rs

@@ -10,6 +10,8 @@ pub enum Route {
     Home,
     #[at("/counter")]
     Counter,
+    #[at("/echo")]
+    Echo,
     #[not_found]
     #[at("/404")]
     NotFound,
@@ -22,6 +24,7 @@ fn switch(routes: Route) -> Html {
         Route::Home => html! { <IndexPage /> },
         Route::Counter => html! { <CounterPage /> },
         Route::NotFound => html! { <NotFound /> },
+        Route::Echo => html! { <EchoPage /> },
     }
 }
 

src/frontend/components/nav.rs

@@ -42,6 +42,7 @@ pub fn nav_bar() -> Html {
     for (route, title) in [
         (Route::Home, "Home"),
         (Route::Counter, "Counter"),
+        (Route::Echo, "Echo"),
     ] {
         let active_item = if let Some(ref location) = maybe_location {
             let path = location.path();

src/frontend/pages.rs

@@ -1,7 +1,9 @@
 pub mod index;
 pub mod counter;
+pub mod echo;
 pub mod _404;
 
 pub use counter::CounterPage;
+pub use echo::EchoPage;
 pub use index::IndexPage;
 pub use _404::NotFound;

src/frontend/pages/echo.rs

@@ -0,0 +1,114 @@
+use futures::{FutureExt, StreamExt};
+use std::rc::Rc;
+use std::time::Duration;
+use wasm_bindgen::JsCast;
+use web_sys::HtmlInputElement;
+use yew::prelude::*;
+use yew::{function_component, html, use_state_eq, Callback, Html, InputEvent};
+
+#[derive(Clone, PartialEq, Default)]
+struct ReducibleString(String);
+enum StringReducer {
+    Append(String),
+}
+
+impl Reducible for ReducibleString {
+    type Action = StringReducer;
+    fn reduce(self: Rc<Self>, action: Self::Action) -> Rc<Self> {
+        match action {
+            StringReducer::Append(string) => Rc::new(Self(format!("{}{}", self.0, string))),
+        }
+    }
+}
+
+#[function_component]
+pub fn EchoPage() -> Html {
+    let response = use_reducer(ReducibleString::default);
+
+    let name = use_state_eq(|| String::new());
+    let name_setter_for_input = {
+        let name = name.clone();
+        Callback::from(move |ev: InputEvent| {
+            let name_writer = name.setter();
+            let Some(target) = ev.target() else {
+                return;
+            };
+            // Events can bubble so this listener might catch events from child
+            // elements which are not of type HtmlInputElement
+            let input = target.dyn_into::<HtmlInputElement>().ok();
+
+            if let Some(input) = input {
+                name_writer.set(input.value());
+            }
+        })
+    };
+
+    let start_sse = {
+        let name = name.clone();
+        let response = response.clone();
+        Callback::from(move |_| {
+            let response = response.clone();
+            let url = format!("/sse/echo?s={}", *name);
+            let mut eventsource = match gloo::net::eventsource::futures::EventSource::new(&url) {
+                Ok(eventsource) => eventsource,
+                Err(err) => {
+                    gloo::console::error!(format!("failed to open event source: {}", err));
+                    return;
+                }
+            };
+            let mut subscription = match eventsource.subscribe("message") {
+                Ok(subscription) => subscription,
+                Err(err) => {
+                    gloo::console::error!(format!("failed to subscribe on event source: {}", err));
+                    return;
+                }
+            };
+            wasm_bindgen_futures::spawn_local(async move {
+                loop {
+                    futures::select_biased! {
+                        message = subscription.next().fuse() => {
+                            let Some(data) = message else {
+                                continue
+                            };
+                            let (_, event) = match data {
+                                Ok(data) => data,
+                                Err(err) => {
+                                    gloo::console::error!(format!("failed to fetch data from event source: {}", err));
+                                    continue;
+                                }
+                            };
+
+                            let Some(data) = event.data().as_string() else {
+                                continue
+                            };
+
+                            response.dispatch(StringReducer::Append(data));
+                        }, // subscription.next
+                        _ = gloo::timers::future::sleep(Duration::from_secs(5)).fuse() => {
+                            break
+                        },
+                    }
+                }
+
+                gloo::console::log!("eventsource 5: ", format!("{:?}", eventsource.state()));
+            });
+        })
+    };
+
+    if (*response).0.len() > 0 {
+        let response = (*response).clone().0;
+        html! {
+            <>
+                {response}
+            </>
+        }
+    } else {
+        let name = (*name).clone();
+        html! {
+            <>
+                <input value={name} oninput={name_setter_for_input} />
+                <button onclick={start_sse}>{"Hi"}</button>
+            </>
+        }
+    }
+}